Rice consumption and nutrition problems
NUTRITIONAL PROBLEMS IN RICE-CONSUMING COUNTRIES
The nutritional situation in rice-consuming countries varies substantially depending on a web of interacting socio-economic, developmental, cultural, environmental and dietary factors. Regardless of the region, most rice- dependent economies have high population growth rates, low rice yields
Income elasticity
for rice, 1988
Country Economically
active population,
TABLE 9 (continued)
Country Economically Percent Cropped Literacy Life Per caput Rough rice income
active population, agriculture in land per
1985 rate.
economically caput, 1985 expectancy GNP, yield,
at birth, 1987 elasticity
1988 Province of China Thailand
b Figures in parentheses are 1980 values.
Sources: Asian Development Bank. 1989: IRRI. 1991a (rough rice yield): Huang, David and Duff, 1991 (income elasticity).
24 Rice consumption and nutrition problems (except for China, Korea and Indonesia) and low gross national product (IRRI, 1989), (Table 9). Landholdings are small, low percentages of the population are economically active and literacy rates are variable in tropical Asia (Asian Development Bank, 1989), (Table 9).
Malnutrition is not just a problem of food availability; it is also a problem of income and food and income distribution (Flinn and Unnevehr, 1984).
Because rice is a major source of income in rural Asia as well as a key component of private expenditure, increased productivity can reduce malnutrition both by increasing the incomes of the poorest rice producers and by increasing the availability of rice and the stability of rice prices.
A summary of nutritional problems prevalent in rice-consuming countries is presented. As 90 percent of the rice is produced and eaten by populations in Southeast Asia, the description is biased toward that region.
Among the major nutritional problems prevalent in rice-consuming countries, inadequate and unbalanced dietary intake is the most important one. In combination with other compounding factors, it leads to widespread prevalence of protein-energy malnutrition (PEM), nutritional anaemia (particularly from iron deficiency), vitamin A deficiency and iodine deficiency disorders (Chong, 1979; Scrimshaw, 1988; Khor, Tee and Kandiah, 1990).
In addition, dietary deficiencies of thiamine, riboflavin, calcium, vitamin C and zinc are prevalent in many areas but often are not manifested in overt clinical syndromes.
These nutritional problems are not caused directly by the consumption of rice per se but reflect an overall impact of multiple causative factors similar to those of other developing countries where rice is not a major staple.
Food availability and dietary intake
Data on availability of food and nutrients are derived from FAO Food balance sheets and from nutrition surveys and studies on food consumption.
Food balance sheet data provide estimates of per caput food and nutrient availability taking into consideration food production, imports, exports, non-food uses, manufactured foods and wastage at the retail level. A comparison of daily nutrient supply for developed and developing countries (FAO, 1990b), (Table 10) shows that the Far East has the lowest availability
Rice in human nutrition 25
of fat, retinol, thiamine, riboflavin and ascorbic acid. Individual data pertaining to rice-eating countries (Table 11) show that in addition to dietary energy many rice-consuming countries have unsatisfactory levels of fat, calcium, iron, riboflavin and ascorbic acid. When wastage at the household level, including cooking loss, is taken into account the supply situation becomes more precarious.
Available data from nutrition surveys are often fragmentary and do not pertain to all countries. Even when data are available they may not always be representative and are often out of date. Table 12 presents examples of available data on average consumption of energy and protein from selected countries. Overall this consumption is unsatisfactory when compared with availability of these nutrients, except in China and Mauritius (Table 11).
There appears to be a large gap between availability of food and actual consumption, which indicates a significant influence of factors related to food access and utilization. However, these intake values strongly suggest the possibility of widespread prevalence of protein-energy malnutrition in young children. There is also enough indication from available consumption studies to suggest that special groups such as young children and pregnant mothers have dietary intakes that are low in energy, protein, vitamin A, iron, riboflavin and calcium.
Rural family consuming a rice- based meal
TABLE 10
Comparative daily provisional supply of nutrients per caput in developing and developed countries, 1986-88 Source: FAO. 1990b.
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TABLE 11
Daily per caput nutrient supply in 36 countries with rice as staple
Country Energy Protein Fat Calcium Iron Retinol Thiamin Riboflavin Niacin Ascorbic (kcal) (g) (g) (mg) (mg) (µg) (mg) (mg) (mg) acid
28 Rice consumption and nutrition problem
TABLE 11 (continued)
Country Energy Protein Fat Calcium Iron Retinol Thiamin Riboflavin Niacin Ascorbic
(kcal) (g) (g) (mg) (mg) (µg) (mg) (mg) (mg) acid Source: FAO Statistics Division, 1987-89 average.
General nutritional status
Table 13 provides information on some important indicators of overall nutritional status for 34 rice-consuming countries (UNICEF, 1991). It clearly indicates that in most of these countries the incidence of low birth weight, infant mortality and mortality under five is high and the prevalence of moderately and severely underweight children is alarmingly higher. The life expectancy is also low. About half the people in South Asia and sub- Saharan Africa receive inadequate energy for an active working life. Some 470 million undernourished people live in South Asia. All these data are a reflection of the poor general nutritional status of the population.
Protein-energy malnutrition
Protein-energy malnutrition still prevails widely in many rice-consuming countries. The low-income developing countries among the group are primarily and seriously affected. PEM is manifested by widespread growth retardation among preschool children. For example, nutrition surveys have
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TABLE 12
Average daily energy and protein intake in selected rice-consuming countries
Country Year of data Energy intake Protein intake
( kcal/caput/day ) ( g/caput/day ) collection
Bangladesh China Colombia Côte d'lvoire Guyana lndonesia Madagascar Mauritius Nepal Philippines Sri Lanka Viet Nam
1980/81 1982 1981 1979 1976 1980 1962 1983 1985 1987 1980/81 1988
1 943 2 485 2 223 2 140 2 054 1 800 2 223 3 043 2 440 1 753 2 030 2 142
48.0 67.0 55.3 55.7 55.5 43.0 55.3 79.4 66.0 49.7 49.9 59.1
Source : FAO country profiles and national nutrition surveys.
shown combined prevalence rates of 71 and 17 percent for moderate and severe underweight among preschool children in Bangladesh and the Philippines, respectively. In many other rice-consuming countries.
particularly India, Laos, Madagascar, Nepal, Sierra Leone, Sri Lanka and Viet Nam, PEM is a major factor directly or indirectly contributing to high under-five mortality.
Vitamin A deficiency
Vitamin A deficiency is widespread in rice-consuming populations of tropical Asia (DeMaeyer, 1986). The most severely affected countries include Bangladesh, India, Indonesia, Myanmar, Nepal, the Philippines, Sri Lanka and Viet Nam. Vitamin A deficiency is also a problem in northeastern Brazil.
30 Rice consumption and nutrition problem
TABLE 13
Nutrition indicators for some selected rice-consuming countries
Country a Under-five Infant Percent Percent Life Daily
mortality b mortality c low birth- moderate expectancy f per caput as percent
I989 I989
1980-88 weight d underweight, and severe 1989 energy supply
children of requirement
1980-89 0-4 yr e 1984-86 Dominican Republic Philippines
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TABLE 13 (continued)
Country a Under-five Infant Percent Percent Life Daily
mortality b mortality c low birth- moderate expectancy f per caput as percent 1984-86
1989 1989 weight d and severe 1989 energy supply
children of requirement
0-4 yr e 1980-89 1980-88 underweight,
Mauritius Singapore Hong Kong Japan
29 12 9 6
22 8 7 4
9 7 5 5
24 14 – –
70 74 77 79
121 124 121 122
a Listed in descending order of under-five mortality rate.
c Annual number of deaths of children under one year of age per 1 000 live births.
b Annual number of deaths of children under five years of age per 1 000 live births.
e Below minus two standard deviations from median weight for age of reference population.
d 2 500 g or less.
f The number of years new-born children would live if subject to the mortality risks prevailing for the cross- section of population at the time of their birth.
Source: UNICEF, 1991.
Although it is difficult to determine the exact number of new cases of vitamin A deficiency and xerophthalmia occurring globally each year, available data from Indonesia indicated an annual rate of 2.7 per 1 000 children, leading to an estimate of 63 000 new cases annually for Indonesia.
If a similar rate is applied to Bangladesh, India and the Philippines some 400 000 preschool children in these countries are likely to develop active corneal lesions resulting in total or partial blindness. It has been further estimated that worldwide some 3 million children under 10 years of age are currently suffering from blindness from xerophthalmia, about 1 million of whom are in India. In addition, countless children not presenting active signs of xerophthalmia are vitamin A depleted, a condition associated with decreased resistance to infectious diseases and increased mortality and morbidity.
Nutritional anaemias
Nutritional anaemias, mostly from iron deficiency, are widespread among rice-consuming countries. The causes are low dietary intake of iron, low
32 Rice consumption and nutrition problems
biological availability of iron from food (Hallberg et al., 1977), blood loss caused by intestinal parasites, particularly hookworm, and unfulfilled increased demand associated with rapid growth and pregnancy.
Anaemia is a condition diagnosed when haemoglobin level is below a set level suggested by the World Health Organization (WHO), depending on the age, sex and physiological condition (with adjustments necessary for high altitudes). A WHO estimate for 1980 (DeMaeyer and Adiels-Tegman, 1985) indicated that about 1 300 million of the 4 400 million people in the world suffer from anaemia and 1 200 million of these are from developing countries. Young children and pregnant women are most affected, with global prevalence rates estimated at 43 percent and 51 percent respectively, followed by school age children (37 percent), women of reproductive age (35 percent) and male adults (17 percent).
The highest overall prevalence of anaemia in the developing countries occurs in South Asia and Africa. The prevalence rate of anaemia in South Asia (DeMaeyer and Adiels-Tegman, 1985) was estimated to be 56 percent in children up to 4 years of age, 50 percent in 5- to 12-year-old children and 32 percent in men and 58 percent in women 15 to 59 years old. A higher rate (65 percent) was reported for pregnant women. Slightly lower rates were reported for East Asia, excluding China.
Estimates of anaemia from folate and vitamin B 12 deficiency are not known, but this type of anaemia is reported to occur, particularly in India.
Dietary patterns suggest increased risk in parts of Southeast Asia, but data are inadequate to confirm this.
Anaemia is an important cause of maternal mortality associated with childbirth. In addition, in adults it lowers work performance and has been linked with reduced immune competence and resistance to infection. Mild anaemia may also have far-reaching effects on psychological function and cognitive development.
Iodine deficiency disorders
Iodine deficiency disorder (IDD) is prevalent in many rice-eating populations, particularly in mountainous regions in Brazil, China, India, Indonesia and Malaysia, where the iodine content of soil, water and food is generally low
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(Chong, 1979; Khor, Tee and Kandiah, 1990). IDD is also prevalent in Bangladesh because frequent flooding washes the iodine from the soil. It has been estimated that about 800 million people worldwide are at risk of IDD (United Nations, 1987).Nearly a quarter of those at risk have goitre and over 3 million are estimated to show overt cretinism. Most people at risk are in Asia, including 300 million in China and 200 million in India.
In areas with very high prevalence of iodine deficiency goitre may affect over 50 percent of the population and occurrence of cretinism may vary from 1 to 5 percent. An additional 25 percent may suffer from measurable impairment of mental and motor function. In some remote areas of the Himalayas IDD prevalence of 30 percent has been recorded.
Iodine is essential for normal growth and foetal development and for normal physical and mental activities in adults. Apart from overt signs of IDD, iodine-deficient populations may suffer from a variety of consequences that include reduced mental functions, widespread lethargy, increased stillbirths and increased infant mortality.
Thiamine and riboflavin deficiency
Thiamine and riboflavin deficiencies still exist in many parts of Asia.
Beriberi is a characteristic disease of rice-eating communities, particularly when polished rice is consumed. It is rarely seen in communities where rice is eaten parboiled or undermilled. The replacement of hand pounding by machine mills in rural areas has aggravated the problem (Chong, 1979).
Thiamine and riboflavin availabilities are lowest in Far Eastern diets (FAO, 1990b), (Table 10).
Clinical and experimental studies have suggested that the development of clinical manifestations of beriberi requires a thiamine intake below 0.2 mg per 1 000 kcal. Biochemical signs may be present at intakes as high as 0.3 mg per 1 000 kcal.
Over the years beriberi has tended to disappear as economic conditions have improved and diet has become more varied. Although the prevalence of clinical cases of apparent beriberi in adults has fallen, in many places beriberi in breast-fed infants is seen sporadically in some populations. For example, some rural lactating Thai mothers who only eat rice and salt post-
34 Rice consumption and nutrition problems
partum and who restrict nutritious food are prone to develop thiamine deficiency. The low thiamine content in their breast milk predisposes their breast-fed infants to beriberi.
Angular stomatitis, a clinical sign often attributed to riboflavin deficiency, is also frequently seen in young children, pregnant women and lactating mothers in rice-eating populations in Bangladesh, India and Thailand. In Thai villages riboflavin deficiency has been reported to coexist with thiamine deficiency (Tanphaichitr, 1985).
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